drivers/net/wireguard/queueing.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
  */

 #ifndef _WG_QUEUEING_H
 #define _WG_QUEUEING_H

 #include "peer.h"
 #include <linux/types.h>
 #include <linux/skbuff.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>

 struct wg_device;
 struct wg_peer;
 struct multicore_worker;
 struct crypt_queue;
 struct sk_buff;

 /* queueing.c APIs: */
 int wg_packet_queue_init(struct crypt_queue *queue, work_func_t function,
 			 bool multicore, unsigned int len);
 void wg_packet_queue_free(struct crypt_queue *queue, bool multicore);
 struct multicore_worker __percpu *
 wg_packet_percpu_multicore_worker_alloc(work_func_t function, void *ptr);

 /* receive.c APIs: */
 void wg_packet_receive(struct wg_device *wg, struct sk_buff *skb);
 void wg_packet_handshake_receive_worker(struct work_struct *work);
 /* NAPI poll function: */
 int wg_packet_rx_poll(struct napi_struct *napi, int budget);
 /* Workqueue worker: */
 void wg_packet_decrypt_worker(struct work_struct *work);

 /* send.c APIs: */
 void wg_packet_send_queued_handshake_initiation(struct wg_peer *peer,
 						bool is_retry);
 void wg_packet_send_handshake_response(struct wg_peer *peer);
 void wg_packet_send_handshake_cookie(struct wg_device *wg,
 				     struct sk_buff *initiating_skb,
 				     __le32 sender_index);
 void wg_packet_send_keepalive(struct wg_peer *peer);
 void wg_packet_purge_staged_packets(struct wg_peer *peer);
 void wg_packet_send_staged_packets(struct wg_peer *peer);
 /* Workqueue workers: */
 void wg_packet_handshake_send_worker(struct work_struct *work);
 void wg_packet_tx_worker(struct work_struct *work);
 void wg_packet_encrypt_worker(struct work_struct *work);

 enum packet_state {
 	PACKET_STATE_UNCRYPTED,
 	PACKET_STATE_CRYPTED,
 	PACKET_STATE_DEAD
 };

 struct packet_cb {
 	u64 nonce;
 	struct noise_keypair *keypair;
 	atomic_t state;
 	u32 mtu;
 	u8 ds;
 };

 #define PACKET_CB(skb) ((struct packet_cb *)((skb)->cb))
 #define PACKET_PEER(skb) (PACKET_CB(skb)->keypair->entry.peer)

 /* Returns either the correct skb->protocol value, or 0 if invalid. */
 static inline __be16 wg_examine_packet_protocol(struct sk_buff *skb)
 {
 	if (skb_network_header(skb) >= skb->head &&
 	    (skb_network_header(skb) + sizeof(struct iphdr)) <=
 		    skb_tail_pointer(skb) &&
 	    ip_hdr(skb)->version == 4)
 		return htons(ETH_P_IP);
 	if (skb_network_header(skb) >= skb->head &&
 	    (skb_network_header(skb) + sizeof(struct ipv6hdr)) <=
 		    skb_tail_pointer(skb) &&
 	    ipv6_hdr(skb)->version == 6)
 		return htons(ETH_P_IPV6);
 	return 0;
 }

 static inline bool wg_check_packet_protocol(struct sk_buff *skb)
 {
 	__be16 real_protocol = wg_examine_packet_protocol(skb);
 	return real_protocol && skb->protocol == real_protocol;
 }

 static inline void wg_reset_packet(struct sk_buff *skb, bool encapsulating)
 {
 	u8 l4_hash = skb->l4_hash;
 	u8 sw_hash = skb->sw_hash;
 	u32 hash = skb->hash;
 	skb_scrub_packet(skb, true);
 	memset(&skb->headers_start, 0,
 	       offsetof(struct sk_buff, headers_end) -
 		       offsetof(struct sk_buff, headers_start));
 	if (encapsulating) {
 		skb->l4_hash = l4_hash;
 		skb->sw_hash = sw_hash;
 		skb->hash = hash;
 	}
 	skb->queue_mapping = 0;
 	skb->nohdr = 0;
 	skb->peeked = 0;
 	skb->mac_len = 0;
 	skb->dev = NULL;
 #ifdef CONFIG_NET_SCHED
 	skb->tc_index = 0;
 #endif
 	skb_reset_redirect(skb);
 	skb->hdr_len = skb_headroom(skb);
 	skb_reset_mac_header(skb);
 	skb_reset_network_header(skb);
 	skb_reset_transport_header(skb);
 	skb_probe_transport_header(skb);
 	skb_reset_inner_headers(skb);
 }

 static inline int wg_cpumask_choose_online(int *stored_cpu, unsigned int id)
 {
 	unsigned int cpu = *stored_cpu, cpu_index, i;

 	if (unlikely(cpu == nr_cpumask_bits ||
 		     !cpumask_test_cpu(cpu, cpu_online_mask))) {
 		cpu_index = id % cpumask_weight(cpu_online_mask);
 		cpu = cpumask_first(cpu_online_mask);
 		for (i = 0; i < cpu_index; ++i)
 			cpu = cpumask_next(cpu, cpu_online_mask);
 		*stored_cpu = cpu;
 	}
 	return cpu;
 }

 /* This function is racy, in the sense that next is unlocked, so it could return
  * the same CPU twice. A race-free version of this would be to instead store an
  * atomic sequence number, do an increment-and-return, and then iterate through
  * every possible CPU until we get to that index -- choose_cpu. However that's
  * a bit slower, and it doesn't seem like this potential race actually
  * introduces any performance loss, so we live with it.
  */
 static inline int wg_cpumask_next_online(int *next)
 {
 	int cpu = *next;

 	while (unlikely(!cpumask_test_cpu(cpu, cpu_online_mask)))
 		cpu = cpumask_next(cpu, cpu_online_mask) % nr_cpumask_bits;
 	*next = cpumask_next(cpu, cpu_online_mask) % nr_cpumask_bits;
 	return cpu;
 }

 static inline int wg_queue_enqueue_per_device_and_peer(
 	struct crypt_queue *device_queue, struct crypt_queue *peer_queue,
 	struct sk_buff *skb, struct workqueue_struct *wq, int *next_cpu)
 {
 	int cpu;

 	atomic_set_release(&PACKET_CB(skb)->state, PACKET_STATE_UNCRYPTED);
 	/* We first queue this up for the peer ingestion, but the consumer
 	 * will wait for the state to change to CRYPTED or DEAD before.
 	 */
 	if (unlikely(ptr_ring_produce_bh(&peer_queue->ring, skb)))
 		return -ENOSPC;
 	/* Then we queue it up in the device queue, which consumes the
 	 * packet as soon as it can.
 	 */
 	cpu = wg_cpumask_next_online(next_cpu);
 	if (unlikely(ptr_ring_produce_bh(&device_queue->ring, skb)))
 		return -EPIPE;
 	queue_work_on(cpu, wq, &per_cpu_ptr(device_queue->worker, cpu)->work);
 	return 0;
 }

 static inline void wg_queue_enqueue_per_peer(struct crypt_queue *queue,
 					     struct sk_buff *skb,
 					     enum packet_state state)
 {
 	/* We take a reference, because as soon as we call atomic_set, the
 	 * peer can be freed from below us.
 	 */
 	struct wg_peer *peer = wg_peer_get(PACKET_PEER(skb));

 	atomic_set_release(&PACKET_CB(skb)->state, state);
 	queue_work_on(wg_cpumask_choose_online(&peer->serial_work_cpu,
 					       peer->internal_id),
 		      peer->device->packet_crypt_wq, &queue->work);
 	wg_peer_put(peer);
 }

 static inline void wg_queue_enqueue_per_peer_napi(struct sk_buff *skb,
 						  enum packet_state state)
 {
 	/* We take a reference, because as soon as we call atomic_set, the
 	 * peer can be freed from below us.
 	 */
 	struct wg_peer *peer = wg_peer_get(PACKET_PEER(skb));

 	atomic_set_release(&PACKET_CB(skb)->state, state);
 	napi_schedule(&peer->napi);
 	wg_peer_put(peer);
 }

 #ifdef DEBUG
 bool wg_packet_counter_selftest(void);
 #endif

 #endif /* _WG_QUEUEING_H */
	/* SPDX-License-Identifier: GPL-2.0 */
	/*
	* Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
	*/

	#ifndef _WG_QUEUEING_H
	#define _WG_QUEUEING_H

	#include "peer.h"
	#include <linux/types.h>
	#include <linux/skbuff.h>
	#include <linux/ip.h>
	#include <linux/ipv6.h>

	struct wg_device;
	struct wg_peer;
	struct multicore_worker;
	struct crypt_queue;
	struct sk_buff;

	/* queueing.c APIs: */
	int wg_packet_queue_init(struct crypt_queue *queue, work_func_t function,
	bool multicore, unsigned int len);
	void wg_packet_queue_free(struct crypt_queue *queue, bool multicore);
	struct multicore_worker __percpu *
	wg_packet_percpu_multicore_worker_alloc(work_func_t function, void *ptr);

	/* receive.c APIs: */
	void wg_packet_receive(struct wg_device wg, struct sk_buff skb);
	void wg_packet_handshake_receive_worker(struct work_struct *work);
	/* NAPI poll function: */
	int wg_packet_rx_poll(struct napi_struct *napi, int budget);
	/* Workqueue worker: */
	void wg_packet_decrypt_worker(struct work_struct *work);

	/* send.c APIs: */
	void wg_packet_send_queued_handshake_initiation(struct wg_peer *peer,
	bool is_retry);
	void wg_packet_send_handshake_response(struct wg_peer *peer);
	void wg_packet_send_handshake_cookie(struct wg_device *wg,
	struct sk_buff *initiating_skb,
	__le32 sender_index);
	void wg_packet_send_keepalive(struct wg_peer *peer);
	void wg_packet_purge_staged_packets(struct wg_peer *peer);
	void wg_packet_send_staged_packets(struct wg_peer *peer);
	/* Workqueue workers: */
	void wg_packet_handshake_send_worker(struct work_struct *work);
	void wg_packet_tx_worker(struct work_struct *work);
	void wg_packet_encrypt_worker(struct work_struct *work);

	enum packet_state {
	PACKET_STATE_UNCRYPTED,
	PACKET_STATE_CRYPTED,
	PACKET_STATE_DEAD
	};

	struct packet_cb {
	u64 nonce;
	struct noise_keypair *keypair;
	atomic_t state;
	u32 mtu;
	u8 ds;
	};

	#define PACKET_CB(skb) ((struct packet_cb *)((skb)->cb))
	#define PACKET_PEER(skb) (PACKET_CB(skb)->keypair->entry.peer)

	/* Returns either the correct skb->protocol value, or 0 if invalid. */
	static inline __be16 wg_examine_packet_protocol(struct sk_buff *skb)
	{
	if (skb_network_header(skb) >= skb->head &&
	(skb_network_header(skb) + sizeof(struct iphdr)) <=
	skb_tail_pointer(skb) &&
	ip_hdr(skb)->version == 4)
	return htons(ETH_P_IP);
	if (skb_network_header(skb) >= skb->head &&
	(skb_network_header(skb) + sizeof(struct ipv6hdr)) <=
	skb_tail_pointer(skb) &&
	ipv6_hdr(skb)->version == 6)
	return htons(ETH_P_IPV6);
	return 0;
	}

	static inline bool wg_check_packet_protocol(struct sk_buff *skb)
	{
	__be16 real_protocol = wg_examine_packet_protocol(skb);
	return real_protocol && skb->protocol == real_protocol;
	}

	static inline void wg_reset_packet(struct sk_buff *skb, bool encapsulating)
	{
	u8 l4_hash = skb->l4_hash;
	u8 sw_hash = skb->sw_hash;
	u32 hash = skb->hash;
	skb_scrub_packet(skb, true);
	memset(&skb->headers_start, 0,
	offsetof(struct sk_buff, headers_end) -
	offsetof(struct sk_buff, headers_start));
	if (encapsulating) {
	skb->l4_hash = l4_hash;
	skb->sw_hash = sw_hash;
	skb->hash = hash;
	}
	skb->queue_mapping = 0;
	skb->nohdr = 0;
	skb->peeked = 0;
	skb->mac_len = 0;
	skb->dev = NULL;
	#ifdef CONFIG_NET_SCHED
	skb->tc_index = 0;
	#endif
	skb_reset_redirect(skb);
	skb->hdr_len = skb_headroom(skb);
	skb_reset_mac_header(skb);
	skb_reset_network_header(skb);
	skb_reset_transport_header(skb);
	skb_probe_transport_header(skb);
	skb_reset_inner_headers(skb);
	}

	static inline int wg_cpumask_choose_online(int *stored_cpu, unsigned int id)
	{
	unsigned int cpu = *stored_cpu, cpu_index, i;

	if (unlikely(cpu == nr_cpumask_bits \|\|
	!cpumask_test_cpu(cpu, cpu_online_mask))) {
	cpu_index = id % cpumask_weight(cpu_online_mask);
	cpu = cpumask_first(cpu_online_mask);
	for (i = 0; i < cpu_index; ++i)
	cpu = cpumask_next(cpu, cpu_online_mask);
	*stored_cpu = cpu;
	}
	return cpu;
	}

	/* This function is racy, in the sense that next is unlocked, so it could return
	* the same CPU twice. A race-free version of this would be to instead store an
	* atomic sequence number, do an increment-and-return, and then iterate through
	* every possible CPU until we get to that index -- choose_cpu. However that's
	* a bit slower, and it doesn't seem like this potential race actually
	* introduces any performance loss, so we live with it.
	*/
	static inline int wg_cpumask_next_online(int *next)
	{
	int cpu = *next;

	while (unlikely(!cpumask_test_cpu(cpu, cpu_online_mask)))
	cpu = cpumask_next(cpu, cpu_online_mask) % nr_cpumask_bits;
	*next = cpumask_next(cpu, cpu_online_mask) % nr_cpumask_bits;
	return cpu;
	}

	static inline int wg_queue_enqueue_per_device_and_peer(
	struct crypt_queue device_queue, struct crypt_queue peer_queue,
	struct sk_buff skb, struct workqueue_struct wq, int *next_cpu)
	{
	int cpu;

	atomic_set_release(&PACKET_CB(skb)->state, PACKET_STATE_UNCRYPTED);
	/* We first queue this up for the peer ingestion, but the consumer
	* will wait for the state to change to CRYPTED or DEAD before.
	*/
	if (unlikely(ptr_ring_produce_bh(&peer_queue->ring, skb)))
	return -ENOSPC;
	/* Then we queue it up in the device queue, which consumes the
	* packet as soon as it can.
	*/
	cpu = wg_cpumask_next_online(next_cpu);
	if (unlikely(ptr_ring_produce_bh(&device_queue->ring, skb)))
	return -EPIPE;
	queue_work_on(cpu, wq, &per_cpu_ptr(device_queue->worker, cpu)->work);
	return 0;
	}

	static inline void wg_queue_enqueue_per_peer(struct crypt_queue *queue,
	struct sk_buff *skb,
	enum packet_state state)
	{
	/* We take a reference, because as soon as we call atomic_set, the
	* peer can be freed from below us.
	*/
	struct wg_peer *peer = wg_peer_get(PACKET_PEER(skb));

	atomic_set_release(&PACKET_CB(skb)->state, state);
	queue_work_on(wg_cpumask_choose_online(&peer->serial_work_cpu,
	peer->internal_id),
	peer->device->packet_crypt_wq, &queue->work);
	wg_peer_put(peer);
	}

	static inline void wg_queue_enqueue_per_peer_napi(struct sk_buff *skb,
	enum packet_state state)
	{
	/* We take a reference, because as soon as we call atomic_set, the
	* peer can be freed from below us.
	*/
	struct wg_peer *peer = wg_peer_get(PACKET_PEER(skb));

	atomic_set_release(&PACKET_CB(skb)->state, state);
	napi_schedule(&peer->napi);
	wg_peer_put(peer);
	}

	#ifdef DEBUG
	bool wg_packet_counter_selftest(void);
	#endif

	#endif /* _WG_QUEUEING_H */